The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Vehicles typically include an engine that produces drive torque which is transmitted to one or more wheels through a transmission at various gear ratios. Dual-clutch transmissions generally include an input shaft, an output shaft, two counter shaft gear arrangements, and two clutches. Each of the two gear arrangements is coupled to the output shaft and includes one or more gear sets for transferring torque at various gear ratios. Each of the two clutches couples the input shaft to a corresponding one of the two gear arrangements. During operation, the two clutches are selectively actuated to transmit torque between the input shaft and the output shafts at the various gear ratios via the two gear arrangements.
Transmission control systems have been developed to control operation of the clutches. Specifically, clutch position, clutch torque, and/or clutch slip may be controlled. Some transmission control systems enable the engaged clutch to slip during periods when the transmission is operated in a selected gear. Clutch slip occurs when an amount of torque transmitted by the clutch (i.e., clutch torque) is less than an input torque. The engaged clutch may be allowed to slip to improve clutch response when disengaging the engaged clutch to shift into another gear. In such systems, clutch slip may be controlled by controlling clutch torque. Clutch torque may be controlled by controlling clutch position based on a predetermined clutch torque to position relationship.